Assessment of phenol wet oxidation on CuO/γ-Al2O3 catalysts: Competition between heterogeneous and leached-copper homogeneous reaction paths
| Autor: | Rita R. Zapico, Salvador Ordóñez, Pablo Marín, Fernando V. Díez |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
inorganic chemicals
Process Chemistry and Technology Catalyst support Batch reactor Inorganic chemistry chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Pollution Copper 0104 chemical sciences Catalysis chemistry.chemical_compound Catalytic oxidation chemistry Chemical Engineering (miscellaneous) Phenol Wet oxidation Leaching (metallurgy) 0210 nano-technology Waste Management and Disposal |
| Zdroj: | Journal of Environmental Chemical Engineering. 5:2570-2578 |
| ISSN: | 2213-3437 |
| DOI: | 10.1016/j.jece.2017.04.050 |
| Popis: | Wastewaters containing phenol and related compounds are refractory to biological treatments. Wet air oxidation has been proposed as an alternative. The replacement of the usual homogeneous catalysts by heterogeneous ones would be of great economic and operational benefits. The reaction has been studied in a batch reactor, at different operating conditions (temperature, phenol concentration, and pH), using CuO/γ–Al 2 O 3 as catalyst). The catalyst stability decreases due to copper leaching, solid polymer deposition on the catalyst surface and changes of the catalyst structure. Copper leaching is produced when pH decreases as a consequence of the short chain acids (oxalic and maleic acid) generated during the reaction. The deposition of solid polymer is caused by the reaction of phenol oxidation intermediates. Copper leaching is considerably reduced when pH is controlled during the reaction: at pH 7 and 10, leaching takes place at very low extent (less than 2% catalyst loss). Based on a detailed model for the homogeneous wet air oxidation, it can be concluded that dissolved copper undoubtedly contributes, even in low concentration, to the overall phenol conversion. The homogeneous reaction was found to be considerably faster than the heterogeneous one. |
| Databáze: | OpenAIRE |
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